Theatre was a popular talking point with play houses in all the major towns. Shakespeare’s plays were demanded as much by working class audiences in northern milltowns as by audiences at the great London theatres.

Shelley’s plays deal with the problem of how to rebel against tyranny. Theatre was heavily censored, and this deprived Shelley’s contemporaries of a chance to see the popular Irish actress, Eliza O’Neill, as the courageous and loving Beatrice Cenci in his play, The Cenci.

Cenci is a rich Italian nobleman who gets away with murder by bribing the Pope. He treats his wife and children with sadistic cruelty. When his daughter Beatrice challenges him, he rapes her. Beatrice, her stepmother and brother hire assassins to murder Cenci, only for their plan to be discovered, and they are caught and tried.

Shelley shows that it is the corruption and hypocrisy of the ruling class that leads them to punish Beatrice but not Cenci. The play was not professionally performed until 100 years after Shelley’s death when its greatness was appreciated.

Although Shelley deplored the double standards that allowed the promiscuous king to try his wife for adultery, he was against royalty and was alarmed that radicals were taking up the cause of the equally repulsive Caroline.

In the play, the starving pigs petition King Swellfoot for more hogwash and he orders their slaughter. Meanwhile, his wizards (ministers) have collected evidence against Queen Iona in a green bag, which they say will prove her guilt when it is poured onto her.

When Iona’s trial takes place in the Temple of Famine, she snatches the green bag and pours it on her accusers who turn into vermin.

The goddess Liberty enters to join forces with the goddess Famine, who is sitting upon loaves and skulls. Famine is displaced by the Minotaur, the spirit of revolution, and the pigs scramble for the loaves. Those who reach them turn into bulls.

The Minotaur allows Iona to ride on his back only for as long as they hunt down the vermin. Then they and the remaining pigs gallop off, leaving the bulls alone on stage. The meaning is clear – a popular revolution gets rid of both king and queen.

Shelley added modern elements of ballet and song to his plays Prometheus Unbound and Hellas. These dramas can be read as poems, but both have been successfully performed.

Prometheus, a Greek god [or: Titan] who is a figure of rebellion, has been chained to a mountain by the tyrannical god Jupiter. A vulture eats Prometheus’s liver each day.

Prometheus withdraws his earlier curse on Jupiter and at this, his lover, Asia, travels deep into a volcano to meet Demogorgon, or Necessity. This spirit causes a volcanic eruption by which means Demogorgon can drag Jupiter down with him beneath the earth.

Prometheus is freed and marries Asia. There is then dancing and singing in a long and jubilant celebration of humankind, freed from tyranny.

This message is embodied in Hellas, where the lighting shows a gradual sunset, emphasising the end of empire and the eventual defeat of tyranny.

Shelley’s early death robbed us of what would have been a masterpiece, Charles the First, which is about the English Civil War. He had drafted a first act and left an outline of a second.

The first scene is set at evening at Whitehall – an irony, since this is where Charles will lose his head. A crowd waits to see a procession going to present a masque at court.

It is officially to honour the queen, but also opposes Charles’s policies.

The crowd discuss what they think of Charles and the events of his reign. When the king and his party cross, none of them even look at the people, much less speak to them as Shakespearean leaders would have done.

When the procession arrives with its flaming torches, music, splendid costumes and colourfully decorated chariots, it includes poor people playing on noisy discordant instruments and riding broken-down horses.

This emphasises the gulf between rulers and ruled and sets the pattern for the rest of the play.

Shelley’s plays are rarely studied or performed today. The Cenci’s last performance at a major London theatre was in 1959. But, together with many plays of this period, they deserve to be better known.